Edbot

Support Template

Introduction

Scratch 2.0 is a visual programming language developed by the MIT Media Lab. It can be used for a range of educational purposes from maths and science projects to animated stories with art and music. It provides a stepping stone to the more advanced world of computer programming.

The Edbot Software works with both Scratch 2.0 online and offline versions. It enables your Scratch program to control your Edbots by providing extra Scratch blocks. You'll find the new blocks in the Scratch 'More Blocks' section. Use them like any other Scratch blocks to build your program.

The Edbot Scratch blocks are described below. We’ve called our Edbot 'Bob', but you'll have given yours its own cool name.

Some of the Edbot Scratch blocks need a value or range of values. If you enter an invalid value, Scratch has no way of letting you know and will ignore the block. You can check for errors by opening the Log Viewer window in the Edbot Software.

Motion control blocks

Run motion

block motions

A motion is a set of movements. For example the 'walk forwards' motion instructs your Edbot to walk a few steps forwards. As each servo moves, it will light up in a specific colour to add a stunning visual effect to the motion. Your Edbot comes pre-loaded with lots of motions which are arranged in six categories to make things easier to find:

 basic, dance, fight, greet, gym & sport

Your Scratch script will wait until the motion has completed before moving on.

block get motion no

You can also run a motion by number, starting from 1. This is useful if you want to cycle through the available motions, for example.

Set motion lights

block set motion lights

Normally your Edbot will automatically light up in an aurora of colours when it is performing a motion. This is great to look at, but you may want to set the motion colours yourself. You can turn off the automatic motion lights using this block. You can then use the servo colour block (described below) to set the servo colours before you run a motion. Remember to turn them off when the motion has completed. For example, try setting all servos to green when walking forwards and red when reversing.

Get motion name

block get motion name

Give this Scratch reporter block a motion number and it will give you the motion name in return. If the motion number is unknown, empty text (zero length) will be returned.

Single servo blocks

These blocks let you control individual servos. You can turn a servo on or off, set the colour, speed and position of a servo and get its current position. All of the blocks, with the exception of servo position, offer an "all" option to address all the servos at the same time. If you need to control a set of servos simultaneously, use the multi servo blocks described below.

Set servo on/off

block servo torque

With all servos turned off, your Edbot will be all floppy. Use this block to turn a servo on or off. Note that when you run a motion the servos will be automatically turned on and left on for subsequent instructions.

Set servo colour

block servo colour

Use this block to set the colour of a servo to your chosen colour. Use the same block to turn the servo light off. You can use a number in place of a colour name here, see the list below.

0

Off

-

1

Red

2

Green

3

Yellow

4

Blue

5

Magenta

6

Cyan

7

White

Set servo speed

block servo speed

Set the servo speed for the next servo position block. This can be applied to a specific servo or all servos at the same time. The speed is a number from 1 to 100 inclusive. Setting this to 100 will effectively set the maximum servo speed which can be quite snappy, so mind those fingers!

Set servo position

block servo position

Move an individual servo to the position specified between 0 and 300 degrees. See the diagram below.

servo angle

You need to be a little careful here. It's a good idea to check the current position of the servo before moving it to a new position in case you end up tying your Edbot up in knots. Get the servo position from the current position block described below. If you're unsure you can do something seriously cool like this, to move servo 1 by 10 degrees:

block servo position inc

Get servo position

block get position

This is a Scratch reporter block which gives you the current position of a servo. The position is an angle between 0 and 300 degrees. See the diagram above.

Get servo load

block get load

This Scratch reporter block returns the current load on a servo expressed as a percentage. When a servo is switched on you can gently apply a force to try and move it. The more force you apply, the greater the load. Check out the Scratch handshake project in the sample folder for a cool example.

The load is directional and ranges from -100 to +100.

Multi servo blocks

These blocks allow you to control a set of servos simultaneously.

Set servos on/off

block servo torques

Turn a set of servos on or off. Specify the servo by number followed by "/" followed by 0 or 1 to turn the servo off or on respectively. Specify multiple servos by repeating the sequence, for example "1/0/2/0/3/1/4/1". Servo number 0 means all servos, so "0/0" will turn all servos off.

Set servo colours

block servo colours

Set the colours of a set of servos. Specify the servo number followed by "/" followed by the servo colour index as defined in the colour table. Specify multiple servos by repeating the sequence, for example "1/3/2/3/3/3/4/3". Servo number 0 means all servos, so "0/3" will set all servos to colour index 3.

Set servo speeds

block servo speeds

Set the speed of a set of servos. Specify the servo number followed by "/" followed by the speed expressed as a percentage greater than zero. Specify multiple servos by repeating the sequence, for example "1/50/2/50/3/50/4/50". Servo number 0 means all servos, so "0/12.5" will set all servos to one eighth speed.

Set servo positions

block servo positions

Set the position of a set of servos. Specify the servo number followed by "/" followed by the position which is an angle from 0 to 300 degrees, see the servo diagram. Specify multiple servos by repeating the sequence, for example "1/250/2/50".

Get servo positions

block get positions

This is a Scratch reporter block which gives you the current position of each servo. Useful for more advanced scripting.

Sensor blocks

Set head IR sensor

block set head ir

Your Edbot continuously sends servo and sensor data to the Edbot Software. However you may need to get the servo data as quickly as possible, for example if you’re doing motion capture. Use this block to turn off the head IR sensor so your Edbot only sends servo data. It’s on by default.

Get head IR sensor

block get head ir

This reporter block returns the current value of the head IR sensor. The IR sensor is mounted on the Edbot's head and measures the distance to an object in front of the Edbot. The sensor was calibrated using the distance between the front edge of the feet and a vertical white A4 card. Note the sensor may give different measurements for different coloured objects placed the same distance away. The reading should be interpreted as an approximate distance in centimetres. The measuring range is 3cm to 30cm rounded to 1 decimal place. A value of 100.0cm means "out of range". In addition you can use the raw value returned from the sensor.

Speech blocks

The following blocks instruct your Edbot to speak! The voice, language, volume, pitch and speed will have been set up during configuration.

Try configuring your Edbot with a different language, if you have the voices available. You can then type text in your chosen language in the speech blocks!

Say

block say

Say the words! This block won’t wait for the speech to finish before continuing to the next block.

Say and wait

block say wait

Say the words! This block will wait for the speech to finish before continuing to the next block.

Current word

block get current word

This reporter block gives you the current word as it is being spoken. It returns empty text (zero length) if your Edbot isn't speaking. Use it to add visual emphasis during speech, such as flashing your Edbot's servo lights on and off. The example below displays the current word in a speech bubble.

block current word example

General blocks

Reset

block reset

This will stop the current command, turn all the servo lights off, set the motion lights / sensor to defaults and halt any speech on a word boundary. It won't turn the servos off however, just in in case your Edbot is in the middle of an amazing acrobatic routine.

Status

block get status

This reporter block can be used to check if your Edbot is connected to the Edbot Software and whether it is enabled or not. The block returns 1 if connected or enabled and 0 if not.